Classification of Designs
Classification of Designs
- COMBINATIONAL
Output only depends on the instantaneous input values.IDEAL: Output responds instantly.REALITY: Propagation delay, spurious outputs ("glitches") that must eventually settle.=> No feedback path exists from the outputs to the inputs.*
- SEQUENTIAL
Circuit contains "memory" (store) so the output may depend on the sequence of previous inputs (since power-up!)REALITY: Output depends on the duration of the inputs.=> There must be at least one feedback path from the outputs to the inputs.* Is this really true? Why?